One of the most northern representatives of the family Atyidae, an amphidromous shrimp Paratya borealis Volk, 1938 (Crustacea: Decapoda: Atyidae), is considered as a junior synonym of Paratya ...compressa (De Haan, 1844 in De Haan, 1833-1850) based on morphological and genetic investigations of the specimens collected in rivers flowing into Peter the Great Bay and Posyeta Bay along the Russian coasts of the Sea of Japan. The study greatly increases the area of distribution of P. compressa to north for more than 1000 km and suggests that the species probably inhabit rivers flowing into the Sea of Japan also along North and South Korean coasts.
Lebbeus sokhobio sp. nov. is described from abyssal depths (3303−3366 m) in the Kuril Basin of the Sea of Okhotsk. The related congeners are deep-water dwellers with a very distant distribution and ...very similar morphology. The new species is separated by minor morphological features, such as the armature of the rostrum and telson, meral spinulation of ambulatory pereiopods and the shape of the pleonal pleurae. This species is the deepest dwelling representative of the genus Lebbeus and the family Thoridae. A list of records of caridean shrimps recorded from abyssal depths below 3000 m is given.
We prove that the quotient of the group algebra of the braid group on 5 strands by a generic cubic relation has finite rank. This was conjectured by Broué, Malle and Rouquier and has for consequence ...that this algebra is a flat deformation of the group algebra of the complex reflection group G32, of order 155,520.
A new symbiotic species of liljeborgiid amphipods, Liljeborgia associata sp. nov., is described from the burrows of the spoon worm Urechis unicinctus (Drasche, 1880) (Annelida: Polychaeta: Echiura: ...Urechidae) in the southern part of Peter the Great Bay and Posjeta Bay in the Sea of Japan. The new species is mostly similar and probably related to Liljeborgia geminata Barnard, 1969, known from the Californian coasts of the USA, and Liljeborgia serratoides Tzvetkova, 1967, described from Posjeta Bay in the Sea of Japan, but can be clearly distinguished from all congeners by morphological features of mouthparts, appendages and telson. The new species is only the fourth in the family Liljeborgiidae to be described from the Russian coast of the northwestern Pacific and the first in association with spoon worms (Echiura).
A new species of the genus Niphargus Schiödte, 1849 (Crustacea: Amphipoda: Niphargidae), co-existing with other stygobiotic amphipods, Diasynurella kiwi Marin and Palatov, 2023 and Pontonyx donensis ...(Martynov, 1919) (Crangonyctidae), is described from a small spring on a shore of Kiziterinka River in Rostov-on-Don City in the mouth of the Don River. Two of the three species in the studied spring, D. kiwi and the discovered Niphargus, belong to microcrustaceans not exceeding the total body size of 3 mm. The new species, Niphargus rostovi sp. nov., represents one of the smallest species within the genus and is mostly related to the Greek Niphargus karkabounasi Ntakis, Anastasiadou, Zakšek and Fišer, 2015, which is also not reaching the body size of 3 mm. One more related undescribed species is found on the Crete Island by the molecular genetic data. These species represent a separate phylogenetic lineage within the “carpathicus” species complex, which diverged from the congeners in the Late Miocene for more than 10 Mya. At the same time, the speciation within the ingroup started about 5–6 Mya, obviously correlating with the drainage of the Euxinian basin of the Eastern Paratethys, connecting the lower Don and southern Greece areas. Niphargus potamophilus Birštein, 1954 is also first recorded from the mouth of the Belbek River in the Crimean Peninsula, closing the known area from the Kuban River delta to Rostov-on-Don area and further along the western coast of the Black Sea to Bulgaria. Analysis of the recent records of long-time lineages of endemic/subterranean/stygobiotic animals unable to disperse for long distances assumed that glacial refugium existed at the mouth of the Don River, along with the South Caucasus (Colchis) and the southern Caspian (Hyrcania), where many species have survived several periods of glaciation since the late Miocene.
We prove the freeness conjecture of Broué, Malle and Rouquier for the Hecke algebras associated to the primitive complex 2-reflection groups with a single conjugacy class of reflections.
A review and partial revision of the diversity of freshwater stygobiotic crustaceans in the territory of the Republic of North Ossetia–Alania, in the North Caucasus, is presented here. Previously, ...two species of the genus Proasellus Dudich, 1925 (Isopoda, Asellidae), P. uallagirus Palatov & Sokolova, 2020 and P. irystonicus Palatov & Sokolova, 2020, and one species of the genus Niphargus Schiödte, 1849 (Amphipoda, Niphargidae), N. alanicus Marin & Palatov, 2021, were described from the hyporhean/underground habitats (hyporhea) in the area. However, further research using an integrative approach has revealed that only a single species of the genus Proasellus (P. uallagirus) is actually widely distributed in the hyporhean riverbed habitats in the area, while the diversity of the genus Niphargus is higher than previously known. Six more new Niphargus species— namely, N. ardonicus sp. nov., N. sadonicus sp. nov., N. fiagdonicus sp. nov., N. tschertschesovae sp. nov., N. osseticus sp. nov. and N. zeyensis sp. nov., were discovered from the various hypogean underground water sources (i.e., springs and seeps) and are described in this article. Their phylogenetic relationships with their congeners, as well as their ecology and known distribution, are discussed. Furthermore, molecular genetic analysis, with an interpretation of the estimated divergence time, suggests that the studied hyporheic/stygobiotic crustaceans started to diverge from related European and Balkan sister species during the Late Miocene, approximately 8–5.8 Mya, with the reduction in the Paratethys and the uplifting of the Caucasus Mountains. Local speciation was led by local geological processes and karst fragmentation during the Late Pliocene and Early Pleistocene periods, starting around 5.3 Mya. The obtained data suggest that the mountainous area of the North Ossetia–Alania could be considered as a post-Pliocene glacial refugium for subterranean and stygobiotic fauna—the first known for the North Caucasus region.
Based on the morpho-genetic study of stygobiotic shrimps from the genus
Xiphocaridinella
Sadowsky, 1930 (Crustacea: Decapoda: Atyidae), a hydrogeological connection of a number of distant caves in ...Central Abkhazia of the southwestern Caucasus is satisfied, which indicates the possibility of using biospeleological studies in some cases to identify karst hydrosystems together with traditional hydrogeological methods. Moreover, a new stygobiotic atyid shrimp from the genus
Xiphocaridinella
,
X. kelasuri
sp. n., is described based on morphology and analysis of mitochondrial cytochrome oxidase I DNA sequences from three distant caves. The new species is genetically divergent from relatives and phylogenetically related to
Xiphocaridinella smirnovi
Marin, 2020, described from the Besletka (=Tskaro) Cave. Recently, the number of described speciesof the genus
Xiphocaridinella
from Caucasus has increased to 13 species, while the diversity of
Xiphocaridinella
found in the Besletka (=Tskaro) Cave is increasing to 3 species, which is higher than in any other known cave where
Troglocaris
-like shrimps have been discovered.
Terrestrial crustaceans are represented by approximately 4,900 species from six main lineages. The diversity of terrestrial taxa ranges from a few genera in Cladocera and Ostracoda to about a third ...of the known species in Isopoda. Crustaceans are among the smallest as well as the largest terrestrial arthropods. Tiny microcrustaceans (Branchiopoda, Ostracoda, Copepoda) are always associated with water films, while adult stages of macrocrustaceans (Isopoda, Amphipoda, Decapoda) spend most of their lives in terrestrial habitats, being independent of liquid water. Various adaptations in morphology, physiology, reproduction, and behavior allow them to thrive in virtually all geographic areas, including extremely arid habitats. The most derived terrestrial crustaceans have acquired highly developed visual and olfactory systems. The density of soil copepods is sometimes comparable to that of mites and springtails, while the total biomass of decapods on tropical islands can exceed that of mammals in tropical rainforests. During migrations, land crabs create record-breaking aggregations and biomass flows for terrestrial invertebrates. The ecological role of terrestrial microcrustaceans remains poorly studied, while omnivorous macrocrustaceans are important litter transformers and soil bioturbators, occasionally occupying the position of the top predators. Notably, crustaceans are the only group among terrestrial saprotrophic animals widely used by humans as food. Despite the great diversity and ecological impact, terrestrial crustaceans, except for woodlice, are often neglected by terrestrial ecologists. This review aims to narrow this gap discussing the diversity, abundance, adaptations to terrestrial lifestyle, trophic relationships and ecological functions, as well as the main methods used for sampling terrestrial crustaceans.
The activity of deep-burrowing macrofauna strongly influences all biogeochemical processes in sublittoral soft sediments. Despite this key role, these organisms are difficult to sample and, thus, ...often remain ignored in environmental studies. This study is the first in comprehensively exploring the diversity of the macrosymbiotic communities associated with the dominant subtidal deep-burrowing invertebrates from the southern part of the Russian coast of the Sea of Japan, represented by the species of the genera
Upogebia
Leach, 1814 (Arthropoda: Crustacea: Decapoda) and
Urechis
Seitz, 1907 (Annelida: Polychaeta: Echiura). The associated symbiotic communities mostly consist of obligate, host-specific species, while those species found in burrows of both hosts are probably using them just as refuges. Most symbionts occurred solitary or in heterosexual pairs, likely due to aggressive and strictly territorial behavior. This is certainly a hidden biodiversity, as more than half of the species reported here were not previously known from these “relatively simple and well-studied” boreal marine ecosystems. Our findings also allowed us to describe a new species belonging to the symbiotic genus
Hesperonoe
Chamberlin,
1919
(Annelida: Polychaeta: Polynoidae), based on morphological and molecular evidences, the latter being here presented for this genus for the first time.
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